The conventional voice telephony-oriented mobile communication systems have been evolved to high speed, high quality packet data-oriented mobile communication system for providing data and multimedia services. In order to support such high speed high quality data transmission services, various mobile communication technologies including 3rd Generation Partnership Project (3GPP) High Speed Packet Access (HSPA) and LTE, 3GPP2 High Rate Packet Date (HRPD) and Ultra Mobile Broadband (UMB), and IEEE 802.16e have been developed.
The current 3rd generation wireless packet data communication systems such as HSDPA, HSUPA, and HRPD use the Adaptive Modulation and Coding (AMC) and channel sensitive scheduling techniques for improving transmission efficiency. With the AMC technique, the transmitter can control the transmission data amount according to the channel condition. That is, the transmitter reduces the transmission data amount to maintain the reception error probability to an intended level when the channel condition is bad and increases the transmission data amount when the channel condition is good to transmit large amount of data while maintaining the reception error probability to an intended level. With the channel sensitive scheduling resource management technique, the transmitter serves the user having good channel status selectively among multiple users so as to increase system capacity as compare to the case allocating the channel to a single user for the service. Such system capacity increase is called multiuser diversity gain. The AMC and channel sensitive scheduling technique is a method for applying most efficient modulation and coding scheme at time for data transmission based on the partial channel status information fed back from the receiver.